Device for carrying out changing-over between add and not-add in motor-operated calculators



l 1970 TAKASHI MURAKAMI 3,528,604

DEVICE FOR CARRYING OUT CHANGING-OVER BETWEEN ADD AND NOT-ADD IN MOTOR-OPERATED CALCULATORS Filed June 7, 1968 United States Patent 3,528,604 DEVICE FOR CARRYING OUT CHANGING-OVER BETWEEN ADD AND NOT-ADD IN MOTOR- OPERATED CALCULATORS Takashi Murakami, Mishima-shi, Shizuoka-ken, Japan, assignor to Tokyo Denki Kabushiki Kaisha (also known as Tokyo Electric Co., Ltd.), Tokyo-to, Japan, a jointstock company of Japan Filed June 7, 1968, Ser. No. 735,466

Int. Cl. G06c 21/00 US. Cl. 23560.26 4 Claims ABSTRACT OF THE DISCLOSURE A device for carrying out change-over between Add and Not-Add in motor-operated calculators, which comprises a 'main lever, a lever connected to a multiplication-and-division key and engageable with said main lever, a lock lever operatively engaged with said main lever, an interlinking means which operates so that when said lock lever is operated by the main lever, a lever operativcly associated with a Not-Add key is operated, and means which is engaged with said lock lever when this lock lever is in operated position thereby to release the engagement between said lock lever and main lever. The interlinking means comprises a torque frame lever one end of which is jointed with said lock lever, and a link which interconnects the other end of saidframe lever with said lever associated with the Not-Add key.

BACKGROUND OF THE INVENTION This invention relates generally to the fields of motoroperated calculators, and more particularly, the invention concerns a new and improved change-over device in a motor-operated recording calculatonwhich device has a mechanism for carrying out change-over between Add and Not-Add during operations such as multiplication and division.

In a motor-operated calculator, when the multiplier and divisor are printed, it is necessary that the calculator is changed over to Not Add state in order to cause no addition of said numerical values. However, in the conventional motor-operated calculators, the mechanism for changing over the calculator Add to Not-Add or vice versa is of extremely complicated construction.

SUMMARY OF THE INVENTION Accordingly, one object of the present invention, in a broad aspect thereof, contemplates to eliminate the above described disadvantages in the changeover mechanism of the conventional motor-operated calculators.

Another object of the present invention is to provide an automatic change-over device between Add and Not-Add operations in the motor-operated calculators, wherein a lever operated by a Not-Add key is interlinked with another lever operated by a multiplication-and-division key, whereby the construction of the change-over mechanism is extremely simplified and the maintenance such as disassembling, inspection, and repair is very facilitated than those of the conventional mechanisms, with simultaneous improvement of the operational accuracy.

The nature, principle, details, and utility of the invention will become more apparent from the following detailed description with respect to a preferred embodiment of the invention when read in conjunction with the accompanying drawings, in which like parts are designated by like reference numerals and characters.

3,528,604 Patented Sept. 15, 1970 BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a perspective view generally illustrating an embodiment of the present invention, and

FIG. 2(a) (b) (c) are profile views each illustrating a different operational state of principal part of the embodiment of FIG. 1.

For consistency in designating directions, terms such as left, right, front, and rear and related terms herein used are in conformance with those observed by an operator who would normally face the device from the left foreground in FIG. 1.

DETAILED DESCRIPTION Referring first to FIG. 1, the rear end of a lever 2 which is to be operated by a multiplication-and-division key 1 is supported by a pivot shaft 3 so that the lever 2 can be swung around the shaft 3 in a vertical plane. The lever 2 is biased upward by means of a tension spring 4. A latch a is provided at the upper end of a main lever 6 which is extended vertically, and the intermediate portion of the main lever 6 is pivotally supported by a stationary shaft 5. The latch portion a is engaging with a lug a provided along the upper edge of the lever 2, and lower portion of the main lever '6 is biased forward by means of a tension spring 7. The lower portion of the main lever 6 is coupled with a multiplication-and-division mechanism (not shown) through a link 8.

In front of the main lever 6, there is provided a horizontal shaft 10, and on this shaft 10, a torque frame lever 11 is pivotally supported. One upwardly extending end portion of the torque frame lever 11 is joined with a lock lever 12 by a pin 13, and this lock lever 12 is provided at its end opposite to said pin 13 with a pawl-like catch b engaged with a stud pin b provided on the upper side face of the main lever 6, said lock lever 12 being biased downward by means of a spring 14.

Through a link 17, the free end of the rearwardly extending portion of the torque frame lever 11 is coupled with the forward end of a lever 16 to be operated by a Not-Add button 15, and the rear end of the lever 16 is pivotally supported by a fixed pin 18 so that the lever 16 may be swung around the pin 18 in a vertical plane, said lever 16 being biased upward by means of a spring 19.

At the rear of the main lever 6, there is disposed a release lever 20 the intermediate portion of which is pivotally supported by a shaft 21, said lever 20 being biased counterclockwise by means of a spring 25. Further, at the rear of the release lever 20, a rotating plate 23 fixedly mounted on a rotary shaft 22 is also disposed, and on the rotating plate 23, there is provided a roller 24 capable of engaging with the rear end of the release lever 20. The lock lever 12 is provided at its rear end with another lug 0 which is disposed to be able to engage with forward end portion c of the release lever 20.

The operation of the change-over device according to the presentinvention will now be explained.

When the multiplication-and-division key 1 is depressed, the lever 2 is rotated downward and the lug a is disengaged from the latch a provided on the main lever 6, and the main lever 6 is rotated clockwise under the action of the spring 7 as clearly seen in FIGS. 1 and 2. Upon the clockwise rotation of the main lever 6, the lock lever 12 is pulled rearward through the pin b and the pawl-like catch b and the torque frame lever 11 is thereby rotated clockwise. The rotation of the torque frame lever 11 pulls down the lever 16 through the link 17 and the device is changed over into the Not-Add state. In this state, as can be clearly seen from FIG. 2(b), the rear end lug c of the lock lever 12 is in a position engaging with the forward end portion c of the release lever 20.

. At this state, when the calculator operates, the rotary shaft 22 is rotated for one complete turn and the roller 24 on the rotating plate 23 depresses the rear end portion of the release lever 20 downward. As a result thereof, the release lever 20 is rotated clockwise and the forward end portion of the release lever 20 pushes up the engagement lug c of the lock lever 12. Then, the pawl-like catch b on the lock lever 12 is disengaged from the stud pin b and, as shown in FIG. 2(0), the lock lever 12, the torque frame lever 11, and the lever 16 are all brought back to their original positions under the action of the spring 14, and the device is released from the Not-Add operational state. However, in this state, the main lever 6 is in a position rotated in clockwise direction from the original position, so that the multiplication and division operations can be carried out.

When the multiplication or the division operation is completed, the lever 8 is driven rearward, thus causing counterclockwise rotation of the main lever 6, whereby the stud pin [1 slides along the lower sloped edge of the catch portion b and finally engages with the pawl-like catch portion b and the whole members are now brought back to their original positions as indicated in FIG. 1 and FIG. 2(a).

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention as set forth in the appended claims.

I claim:

1. A device for carrying out change-over between Add and Not-Add in motor-operated calculators, comprising: a main lever (6), a lever (2) connected to a multiplication-and-division button so as to be operated thereby and engageable with said main lever, a lock lever (12) operatively engaging with said main lever, an interlinking means comprising a frame lever (11) which is coupled with said lock lever and a lever operatively associated with a Not- Add key so that when the lock lever is operated by the main lever said frame lever operates the lever associated with the Not-Add key, and means which is in engagement with said locklever when the lock lever is in its operated position torelease the engagement between said lock lever and main lever.

2. A device as defined in claim 1 wherein said interlinking means comprises a torque frame lever one end thereof is jointed with said lock lever, and a link which interconnects the other end of said torque frame lever with said lever associated with the Not-Add key.

3. A device as defined in claim 1 wherein said main lever is pivotally supported on a stationary shaft, a stud pin is mounted on the upper side face of the main lever so that the stud pin is operatively engageable with a catch provided on said lock lever.

4. A device as defined in claim 1 wherein a latch is provided at the end portion of said main lever, and this latch is operatively engageable with a lug provided along said lever attached to the multiplcation-and-division key.

References Cited UNITED STATES PATENTS STEPHEN J. TOMSKY, Primary Examiner 

